Rudder info please.

[Varooom]

I have always sharpened the leading edge of my rudders but have left the bottom alone, squared off.

I have seen a few boats on Youtube that have the bottom of the rudder kind of "knife edged" for lack of a better term. I have not seen anyone explain this. Is it a good idea or total waste of time. Or could it possibly hurt water flow?

Wondering if any of you have experience with this. Any words of wisdom greatly appreciated.
Thanks for your time,
Varooom

[fweasel]

I don't pretend to be fast enough, or a good enough driver to tell the difference. What I do change, is the length of the rudder. I cut them shorter on my saw boats to reduce drag, leaving them just long enough to provide the steering and stability I need for that size hull.

[Ryanj]

to mu understanding and thoughts to being flat or knife style
Flat i would think would give you a little bit of lift from the rudder, acting like a planning surface maybe a hair of drag
Knife sharp i would think as to no lifting, cutting the water and less drag
This how i think of why and would you see much of a difference more then likely not hard to say.
When i cut mu rudders my monos are knife style and my hydro's are flat

[RaceMechaniX]

A flat bottom edge will add lift to the rudder, knife edging it reduces lift.